How to plot Pie Charts as Markers on a Map Chart in Spotfire

The mapping capabilities in Spotfire have come a long way over the last few years. They are great for visualizing data spatially and looking at trends over a geographic region. There’s a unique feature in Spotfire that lets you plot mini pie charts on the map, instead of the standard markers.

In this tutorial, you’ll learn how to use pie charts as markers on a map chart, as shown in the picture below.

Map charts
Map charts are built using different layers, which are listed below:

Marker layer

Feature Layer

Image Layer

Map Layer

WMS Layer

This post focuses on Marker Layers, specifically on the feature of markering with pies (Map chart >> Marker Layer >> Marker with Pies).

Markers are data points positioned in a geographic area (e.g. the name of a city) or an exact location (with lat & long coordinates). The ability to color, size, and shape map markers make it possible to compare several different variables – I like to think of the map charts as scatter plots on top of a Google-type map.

Markering with Pies takes this a step further and lets you show the map markers (points on the map) as pie charts instead of some other shape (circle, square, etc.)

Most data visualization experts agree that pie charts should generally be avoided, but I think this is an exception where the value derived exceeds the effort required to interpret the data.

Comparing Oil, Water, and Gas ratios
In this example, I’ll demonstrate how to create a map displaying the ratio of oil, water and gas producing from oil & gas wells in New Mexico. Here’s what the pie chart for 1 well would look like:

Wouldn’t it be nice to evaluate all wells at the same time, on one screen? This could be done by Trellising by Well name, but thousands of wells won’t fit on one screen.

Wouldn’t it be even better to plot these on a map to see if a certain part of the field had different ratios? This could help determine where to drill new wells, plan for flowback equipment, facilities, etc.

This is where the marker with pies comes in. Watch the video below to learn how to how to plot pie charts as markers on a map chart.